Atossa Therapeutics shares surge 12.41% premarket as strategic focus on (Z)-Endoxifen and 2026 catalysts drive optimism.

Atossa Therapeutics surged 12.41% in premarket trading following the release of a letter to shareholders highlighting 2025 accomplishments and a 2026 outlook, coupled with recent strategic updates. The company announced a refocused development strategy prioritizing (Z)-Endoxifen for breast cancer and Duchenne Muscular Dystrophy, including FDA orphan drug and rare pediatric disease designations, and progress in clinical trials. Key catalysts cited include upcoming I-SPY 2 trial data and patent updates, which reinforce investor confidence in the drug’s commercial potential. Additionally, the CEO’s recognition as a top healthcare technology leader and the company’s streamlined operations to accelerate core programs further underscored the positive momentum, aligning with the significant premarket price increase.